Build Warrior Abs

I'M KNEE-DEEP INTO A SCENE RIGHT OUT OF X-MEN: MUTANT MUSCLE. Jon Jones, the 6'4", 205-pound UFC light-heavyweight champion, is playing the Vise. I'm cast as Mediocre Man. The Vise is sitting across from me with his legs outstretched, corralling mine. A 10-second battle of leg strength commences. My core is braced, my hip and thigh muscles tensed. I'm trying to prevent the Vise from using his trunks to squeeze my twigs shut. It's futile. After 4 seconds, I'm smoked. We repeat this twice and then switch. I try without success to squeeze his legs shut.

Next, the Vise passes me off to his coach, Phil Nurse, 49, a former European kickboxing champ known as Kru. (That's "teacher" in Thai.) In this scene I am again the victim, this time of an assault on my undertrained core. Kru is standing, his knees slightly bent. I'm inverted, my legs wrapped around Kru's torso. Kru is smiling and counting—slowly—as I do situps. I eke out three before my thrusters flame out.

I'm enduring these indignities at the Wat gym in Manhattan to learn how an elite mixed martial arts fighter strengthens his core. The house specialty is muay Thai—the art of eight limbs. This technique harnesses the striking ability of hands, feet, knees, and forearms (do the math later). All the attacks demand core strength; your hips and abs power knees, kicks, and upper-body strikes—and that's just on offense. On defense, a strong core is even more critical for withstanding punches and kicks and providing stability while grappling.

"The more tired a guy becomes, the more you see his kicks and knees weaken," Jones says. "Kru's training makes me explosive from my core, no matter how long a fight lasts." I'm expecting Kru to pull out a bamboo rod and smash it on Jones's eight-pack, but instead he grabs some pads and starts to play patty-cake. "I do use some unconventional techniques," Kru says. "It's a combination of old-school muay Thai I learned in Thailand and new drills I created." Kru's East-West alchemy, forged over 30 years, maximizes power and endurance. It's potent stuff. Along with Jones, UFC champion Georges St-Pierre and former champ Frankie Edgar make pilgrimages to the Wat to feel Kru's burn.

Impressive, right? But let's say you have no interest in trading knees and elbows at close range. I'm with you, especially considering what I went through at the Wat. Still, who doesn't want a rock-hard core and hips that are powerful and mobile, not to mention the mutant ability to feel stronger as your workout progresses? Read on for the strength and fitness tips I picked up at the Wat to help guys like you reach your goals. No combat required.

Find your threshold
A fight doesn't end when one guy does 12 kicks or 12 punches. Combat sports are ruled by the clock. That's why you don't count reps or sets at the Wat. Instead, you exercise in 3-or 5-minute intervals to simulate rounds in a fight. "The goal is sustained intensity over time," Kru tells me. It's brutally efficient. Time-based training forces you to go as hard as you can for as long as you can and to find your own maximum work rate. You learn to pace yourself—fast.

Think you’re tough? We dare you to try these 15-minute muscle shredders!

To try it, pick three exercises—the pullup, squat thrust, and goblet squat, for example. For each, see how many you can do with good form in 1 minute, with no rest. As soon as you finish pullups, start doing squat thrusts, and as soon as you finish those, start squatting. Rest for 1 minute and do another set. The short-term aim is to improve the total number of reps you can do in a minute. In the longer term, you also want to increase the resistance you use. Typical Kru workouts are variations of this: 10 to 20 rounds of calisthenics, lifting, striking drills, and sparring, and then stretching.

Warm up instantly
Snap, snap, snap: Rope-jumping fighters provide a soothing back-beat at the Wat. Kru favors this warmup because it activates your upper and lower body, cranks up your ticker, and fine-tunes your hand-eye coordination. Try this drill (if the rope is too challenging, do jumping jacks instead): Start with 2 minutes at a gentle pace, jumping with both feet. Then go faster for 45 seconds, followed by 15 seconds of active recovery (that is, jumping at your slower pace). Now jump on your right leg for 45 seconds, with 15 seconds of active recovery, and then repeat with your left leg.

Activate every muscle
Whole-body movements demand greater energy expenditure while also strengthening the muscles that need to work together. Cut to me, suffering once again: Kru is strapped to my back, his legs cinching my waist, and he's choking me. In this exercise, he's the load—155 pounds of twisted steel. I've slowly gone from sitting to kneeling, finally to standing, and then back down to sitting. Fighters do these Thai getups with Kru for 3-minute intervals. Don't have a muay Thai legend to carry around? Then do the Turkish getup: Lie on your back with your legs straight, holding a dumbbell or kettlebell in your left hand with your left arm straight over your chest. This is the starting position. Now raise your trunk. When you're fully upright in a seated position, the weight will be over your shoulder. Holding it steady above your head, use your right hand to help you push yourself into a kneeling position, and then stand up one leg at a time. Reverse the move to return to the starting position. See how many you can do in 3 minutes, alternating arms every 30 seconds. Increase the time from the first to the second workout, and then increase the weight in the third workout.

Wring out your core
Many men do the same core drills over and over. Instead, Kru makes exercises like planks and leg raises progressively harder as his athletes master the basic moves. He schooled me on these gut busters.

A. Plank with knee kick
Assume a pushup position and hold it for 20 seconds. Drop onto your right forearm and push back up, and then drop onto your left forearm and push back up. Alternate sides for 20 seconds. Then, from the pushup position, thrust your right knee to your right elbow and bring it back, followed by your left knee to your left elbow and back. Do this for 20 seconds. That's 1 minute total; take a 1-minute breather. Do three 1-minute rounds until you can finish strong, with explosive knee thrusts. Eventually work up to 2-minute rounds.

B. Pullup with hanging leg raise
Do a pullup, but at the top, add a leg raise: Lift your knees toward your shoulders. Lower your body and, while hanging, do a single-leg raise on each side. Lift each leg as high as you can without letting the nonworking leg move forward. That's 1 rep. Do three 1-minute rounds, resting for 1 minute in between.

Strengthen your legs
A good punch—or really, any athletic movement, from driving a golf ball to throwing a football—requires powerful hip rotation. And hip rotation requires coordination of the legs and core. While the connection is apparent in any sport this side of chess, combat athletes are acutely aware of it for a simple reason: "Think about how much heavier your legs are than your arms," Kru says. In fact, on average, each leg represents 16 percent of your body mass, versus 5 percent per arm. He made me try this three-part leg circuit: Do each exercise for 20 seconds, for a 60-second interval. Rest 60 seconds, and do two more circuits. (Make it harder by holding dumbbells or convincing a stray human to climb onto your back.)

A. Calf raise
From a standing position, rise up onto your toes as high as you can; slowly descend. Repeat.

B. Squat jump
Push your hips back and descend into a half squat. Jump as high as you can and land softly on the balls of your feet. Repeat.

C. Split jump
From a staggered stance, drop into a lunge; then jump and switch legs midair so you land with the opposite leg forward. Repeat.

I'm out of the ring now, luckily. Kru's playing a beefed-up version of patty-cake with Jones: He's holding pads and calling out combinations. Jones obliges with punches that thud and kicks that boom. In 5 minutes, Jones throws 55 punches, 10 knees, and 35 kicks. It's a powerful display of sustained intensity. Beginners usually find themselves out of breath after a few punches and kicks. Conditioning is one reason Kru always includes striking drills early in training. The other reason is mental. "Whether you're throwing a punch or blocking one, you have to be 100 percent there in the moment," Kru says. "Learning to focus is one of the great benefits of muay Thai, along with learning to do more with your body, which gives you greater confidence."

He's right. Kru's drills made me push beyond my threshold, and it felt great, once I regained my breath. Plus, I went toe-to-toe with a UFC champ, something I'll be able to tell my kids. It was only leg wrestling, of course, but I won't tell them if you won't.